SELECT COUNT(COLUMN_NAME) FROM TABLE[COLUMN_NAME is NOTNULL column] instead of
SELECT COUNT(*) FROM TABLEMy impression was that while for COUNT(*), DB has to do a complete scan of the table, for COUNT(COLUMN_NAME), it require to scan the COLUMN only. But then, I dont know why, I just decided to google it. And I came across this AskTom Entry where it says it is just a myth that COUNT(COLUMN_NAME) is faster than COUNT(*).
I dont know how different DBs behave in this matter?
What u guys think of it? What are ur experiences?